1. Field of the Invention
The present invention generally relates to a lamp structure using Light Emitting Diodes (LEDs) as light sources. More particularly, the present invention relates to the structure of a lamp device for ensuring good heat radiation through distributed heat emission portions, providing a uniform flat fluorescent light source, and offering a pleasing appearance.
2. Description of the Related Art
In general, a lamp device used for outdoor purposes, mainly a street lamp, illuminates the surrounding area on dark or rainy days by turning the lamp on or off. The lamp preferably is installed high on a lamp post and uses commercial electrical power. There are several types of street lamps, including road lamps for illuminating roads at night from the sides of the roads, nightwatch lamps for preventing crimes, and garden lamps installed in parks or gardens for illumination and decoration purposes.
A variety of light sources are available for such lamp devices, such as high-pressure mercury lamps, fluorescent lamps, natrium lamps, etc. The recent trend is in favor of LED (light-emitting-diode) street lamps characterized by low power consumption, low heat emission, and high brightness. Such LED lamps overcome problems with heat emission and lamp life.
Typically, a ballast is installed inside the lamp device to supply power to the light source. In addition, a leakage breaker, a power controller, and the like are installed to the lamp device. The power controller, which may include a timer and a brightness sensor, controls power supply to the light source so that the light source emits light at a predetermined or higher luminance at night or other dark conditions.
A conventional LED lamp device is configured such that the LED light sources are concentrated in a predetermined small housing. Therefore, the conventional LED lamp device creates much glare and makes it difficult to obtain a uniform flat illumination like a fluorescent light source.
Moreover, because much heat is emitted, a heat radiator is additionally required. In many cases, the heat radiator is larger than the lamp device and has a poor appearance. Also, the conventional LED lamp device is limited to the function of a street lamp.
Meanwhile, a transceiver (including a relay) collects data for wireless terminals and transmits them to a switching network in a wireless communication system. The transceiver amplifies a transmission signal by use of a high-power amplifier within a body and radiates the transmission signal through an antenna device. The antenna device transmits a signal received from the wireless terminal to the transceiver for wireless communication, so that the received signal is processed. The antenna device is installed high on the rooftop of a building or on a tower and the transceiver is positioned within the building or under the tower.
In the wireless communication system, the antenna device is installed high to maximize the propagation distance of a radio signal. In an urban area, typically, a post is put up on the rooftop of a building, a fixture is mounted onto the post, and a communication antenna is installed to the fixture.
Although the antenna device for the wireless communication system should be installed at an appropriate position to enable reliable wireless communications, its site is hard to secure because the antenna device is considered as an obstacle to a living environment and thus is unwanted.
Especially in an urban area where people enjoy wireless communication services highly frequently, high cost is another obstacle to the siting of the antenna device.
Surveillance cameras are more unwelcome and thus difficult to install.
In the meantime, street lamps for illuminating roads and nightwatch lamps are installed to their separate posts downtown. Antenna devices, street lamps, nightwatch lamps, etc. are installed to separate posts although they commonly require a power supply and a communication function. Accordingly, there are too many unnecessary disfiguring posts downtown.